Problem: $\dfrac{2}{3} - \dfrac{4}{12} = {?}$
Explanation: $ = {\dfrac{2 \times 4}{3 \times 4}} - {\dfrac{4 \times 1}{12 \times 1}} $ $ = {\dfrac{8}{12}} - {\dfrac{4}{12}} $ $ = \dfrac{{8} - {4}}{12} $ $ = \dfrac{4}{12}$